Electric switch



J. KRUITHOF ET AL Feb. 4, 1958 ELECTRIC SWITCH 6 Sheets-Sheet 4 Filed April 3, 1952 INVENTORS J. KRUITHOF L-. J. G. NYS

Jl L. J. DONCEEL W2 A TTOR/VE Y Feb. 4,1958 J. KRUITHOF ET AL 2,822,431

ELECTRIC swxwcn Filed April 331952 e Sheets-Sheet 5 INVENTORS J. KRUITHOF L.J.G. NYS

J.L.J. DONCEEL ATTORNEY Feb. 4, 1958 J. KRUITHOF ET AL ELECTRIC SWITCH Filed April 3, 1952 6 Sheets-Sheet 6 QUE INVENTORS J. KRUITHOF' L..'J. G. NYS L.J.

United States Patent ELECTRIC SWITCH Jakob Kruithof, Louis Jacques Ghislain Nys, and Jules Louis Joseph Donceel, Antwerp, Belgium, assignors to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application April 3, 1952, Serial No. 280,252

Claims priority, application Netherlands April 13, 1951 Claims. (Cl. 179-2754) The invention relates to an electric switch, e. g. for use in telephone systems, and more particularly to a switch of the type disclosed in the Belgian Patent No. 488,634 (J. Kruithof 40) which is essentially a multiswitch, i. e. a switch with a plurality of inlets and a plurality of outlets with means for the interconnection of any one inlet with any one outlet.

The switch disclosed in that patent included two main parts: the contact bank and the operating mechanisms for establishing a connection between an inlet and an outlet. The contact bank formed a three-dimensional lattice of spaced crossing points between conductors respectively belonging to a first and to a second set. Parallel rows of such crossing points could then be bridged by means of contact fingers and the operation of these contact fingers was controlled by means of a crossbar arrangement, i. e. a set of clutch or select bars and another set of hold or actuating bars permitting to select a particular contact finger by using a number of electro-magnets controlling these bars which is appreciably smaller than the total number of fingers.

The object of the invention is to improve the type of switch described above, one particular object being a reduction in the number of select or clutch bars which are necessary for a switch having a predetermined num ber of outlets.

A feature of the invention resides in an electric switch with a plurality of inlets and a plurality of outlets and comprising a first set of fixed parallel conductors, i. e. outlet conductors, a second set of parallel conductors substantially perpendicular to those of the first set and interleaved therewith so as to form a three-dimensional lattice of spaced crossing points, parallel rows of which, extending in a direction substantially perpendicular to both sets of conductors, can be bridged by means of outlet contact fingers, one for each row and movable substantially perpendicular to both the first and the second sets of conductors, while furthermore said conductors of the second set are used as intermediate conductors between conductors of the first set, i. e. outlet conductors, and fixed conductors of a third set of conductors, i. e. inlet conductors, whereby each connection between an inlet and an outlet is established via one or more intermediate conductors in series.

The above mentioned and other objects and features of the invention will become more apparent and the invention itself will be best understood by referring to the following description of embodiments taken in conjunction with the accompanying drawings which represent:

Fig. 1, a block diagram of a multi-switch;

Fig. 2, a schematic representation of a multi-switch showing the various contacts;

Fig. 3, a schematic representation of a modified multiswitch showing the various contacts;

Fig. 4, a schematic representation of the mechanical parts necessary for the operation of a multi-switch as shown in Fig. 3;

Fig. 5, a schematic representation of a partial modification for the switch shown in Fig. 4;

Fig. 6, a schematic representation of an embodiment of a multi-switch in accordance with the invention;

Fig. 7, a schematic representation of the mechanical parts necessary for the operation of a multi-switch as shown in Fig. 6;

Fig. 8, a perspective view of part of the multi-switch schematically shown in Figs. 6 and 7; I

Fig. 9, a perspective view of another part of the multiswitch schematically shown in Figs. 6 and 7;

Fig. 10, a perspective view of yet another part of the multi-switch schematically shown in Figs. 6 and 7;

Fig. 11, the manner in which Figs. 8, 9 and 10 should be assembled.

Referring to Fig. 1, the latter shows the general principle of a multi-switch M with m inlets and n outlets. Each of these inlets and outlets may, of course, include any number of conductors, i. e. p, which are used for each connection from any one inlet to any of the outlets.

Referring to Fig. 2, the latter shows a schematic arrangement for the electrical contacts which are needed for the various connections in the multi-switch M, these contacts being numbered in accordance with the particular connection which the contact can effect, e. g. contact ij provides for the connection of the ith inlet to the jth outlet. For Fig. 2 and also in Figs. 3 and 6, it should be noted that the fact several conductors may be needed for each connection, is disregarded in order not to complicate the figures.

Referring to Fig. 3, this represents a modification of Fig. 2, in which two-way contacts are used, i. e. contact 11-2 provides for the connection between the first inlet and either the first or the second outlet, in accord ance with the sense of displacement of the contact. The principle of such an arrangement is also well known and has, for example, been disclosed in the Belgian Patent Number 501,688 (G. X. Lens 44).

Referring to Fig. 4, the latter is a known arrangement representing schematically the necessary mechanical parts for operating the contacts included in the multiswitch M schematically shown in Fig. 3.

The Belgian Patent Number 477,334 (G. X. Lens 37) discloses a contact bank with a plurality of horizontal conductors interleaved with a plurality of vertical conductors so as to form a three-dimensional lattice of spaced crossing points between conductors of the first set and conductors of the second set, i. e. between inlet conductors and outlet conductors. The latter can generally be assumed to be fixed conductors, while the former are resilient or at least portions of these are resilient so as to permit the necessary displacement to establish contact with a corresponding outlet conductor. Alternatively, these horizontal conductors can be provided with suitable contact extensions and therefore only these need be resilient so that they may be displaced to effect contact with an outlet conductor. As disclosed, for example, in Belgian Patent Number 501,688 (G. X. Lens 44), contact fingers are used to displace the contact extensions provided on the horizontal conductors, in order to establish the connection. These contact fingers as disclosed in said Belgian patent, are located at right angles to both the horizontal and the vertical conductors and they will generally be used to drive a whole row of contacts by displacing the fingers longitudinally in one or the opposite sense. Accordingly, by referring to Fig. 3, these contact fingers, although they are not shown in that figure, can be assumed to be located substantially at right angles to both the inlet and the outlet conductors.

These fingers are, however, schematically represented in Fig. 4, e. g. F will be used to drive a plurality of contacts 11-2, only one of which is shown in Fig. 3 although, in general, there will be a number p of such contacts in accordance with the numberof conductors which are used for each connection between any inletand any outlet.

Fig. 4 is more particularly related to-the mechanism necessary for the operation of the fingers .such as F and shows selective means for selecting a vertical row of fingers, these selective means comprising avertical or select bar corresponding to each vertical row or fingers, e. g. vertical bar V for the fingerssuchas F Only the first two (V V and the last (V,, ,,)'ver-tical bars have been shownbut it is evident that thenumber of vertical bars is immaterial anddepends on the capacity of the switch. The selectionof a vertical row of fingers is essentially a clutch operation since the fingers will not be actually displaced. As soon as this selectionis per.- formed, actuating and holding means will be used to cause the displacement of a particular selected finger. This has also been schematically represented in Fig. 4 .by horizontal or hold bars of which only the first two (H H and. the last (H have been shown.

Therefore, referring to Figs. 3 and 4, and assuming a connection-is desired between inlet No. l and outlet No. l, the contacts suchas 11-2 and accordingly the finger F should be operated. The vertical select bar V will thus be rst displaced, whereafter the displacement of the horizontal hold bar H will provoke the displacement of the finger F which is located-at the cross point of the bars V and H Various means can beused to cause the displacement of the select bars and the hold bars but Fig. 4 shows in a schematic manner that servo mechanisms are used to cause the displacementof both types of bars..-An electromagnet such ash/M is first of allused to select-a vertical bar, i. e. V and as soon as thisselection is performed, a common bar H will be displaced under the control of the servo-magnet VS, the latter displacement causing the movement of the selecte vertical bar, i. e. V

A servo-magnet can also be used to control the movements of the horizontal bars and al hough each horizontal bar such as H will first of all be selected by the operation of a corresponding electro-magnet, i. e. Hit I the actual operation will heperforrned under the control of the common bars VL and VR which arecontrollcd by the servo-magnets HSL and HSR. The use of two common bars and two servo-magnets is here necessitated in view of the fact that it is desirable to displace the horizontal bars such as H in two opposite senses resulting in the displacement of the corresponding fingers, i e. F also in two opposite senses. This is schematically indicated in Fig. 4 by the arrows f f' for. the horizontal bars and f f' for the fingers. Inithis manner, depending upon the sense of displacement of the horizontal bar, e. g. H and assuming the vertical bar V has first of all been displaced, a connection can be established via the contacts 11-2 either between inletNo. l and outlet No. 1, or between said inlet. and outlet No. 2.

The-use of a servo-magnet is particularly advantageous when the horizontal bars are movable in two opposite senses, sinceif this wereavoided, two electro-magnets would have to be used for each horizontal-bar resulting in the use of twice as many electro-magnets such as HM lfthe number of inlets and accordingly the number of horizontal bars is fairly considerable the use of a servomechanism will certainly be advantageous in such a case.

Fig. 5 shows a partial modification of the controlling arrangement shown in Fig. 4 andrepresents acode bar mechanism CB,.also called permutation barmechanism, by means of whichthe number ofelectro-magnets such as VM is appreciably reduced, these magnetsbeingreplaced by a smaller number'of so-called code'bar mag:

' nets such as CM a plurality of whichrnay, besimultaneaseaeal ously energized in different combinations, resulting in the selection of a particular vertical bar such as V corresponding to a particular combination. Such code bar mechanisms generally operate on a binary basis, since electro-magnets are essentially two-condition devices and such a mechanism is for example disclosed in the Belgian Patent Number 493,326 (0. BrackeG. X. Lens 24-46).

Fig. 6 shows a schematic representation of the electrical connectionsfor a modified multi-switch M. Instead of establishing a direct contact between an inlet and an outlet, e. g. between inlet No. 1 and outlet No. 1 via contact 11-2 when the latter is displaced towards the left, each inlet conductor is first directed to either one of two intermediate horizontal conductors, thereby affording an additional selection of one out of two. This principle will be exemplified by referring to a connection between inlet No. l and any one of the first four outlets, i. e. Nos. 1-4. Assuming it is desired to establish a connection between inlet No. l andoutlet No. 3 contacts 1-b and 13-4 will be closed, the latter towards the left, whereby the connectionwill be established via these contacts and the link (in dotted line between terminals P and P The purpose of. showing the link between terminals such as P andP' in dotted lines will be explained later but unless otherwise stated it canbe assumed that there is a through connection between such terminals.

Referring to Fig. 7, the'latter schematically shows the mechanical parts for operating a multi-switch as represented in Fig. 6. As in Fig. 4, only the first horizontal row of contact fingershas been partially represented but it should, of course, be understood that similarhorizontal rows of fing ers are provided for each-inlet. These fingers arelabelled in the same manner as those shown in Fig. 4, in order to show correspondencebetween the fingers and the contacts which they control. E. g. in Fig. 7, finger 'F is the finger controlling'contacts such as 11-2 and 13-4. Two additional fingers per inlet have'also been representcd'in Fig. 7', i. e. F and P and are respectively used to control the contacts such as in, 2a, ma and 1b, 2b, mb, Accordingly, referring to the example of a connection between inlet No. l and outlet No, 3, this will be achieved by displacingfinger F and alsofinger-F Whereas'the sense of displacement, i. e. f or f2, is significant for the finger F since in one case it will drivethe contacts 11-2 and 13-4 to the left, and in the other case to the right, it will be observed from Fig; 6'that whether'contactssuch as 1b are displaced to theright or to'the left, istotally immaterial. This can be readily understood" from'Fig. 7 whichshows that the fingers such as F and F which will hereinafter be calledintermediate contactfingers and the fingers such as F F F which will hereinafter be called outlet contact fingers, are all displaced under the control Ofi'lh same horizontal bar i. e. H The latter therefore acts as commonactuating means for both types of fingers; Type should be understood'here as relevant to purpose rather than actual construction, since they mightwell'be of similar design;

' Since the horizontal bar such as H can be displaced in two'opposite senses, i. e. f or. f thereby affording a selection of one out of two which is used to obtain a connection either to the odd numbered outlets or to the even numbered outlets, this selection of one out of two can only be usedonce and not again for the fingers such as F 15 and F whichshould therefore establish the same electrical connection irrespective of the sense of displacement of the horizontal bar, as clearly indicated. in Fig.6.

The intermediate contact fingers; such asF are also selected in vertical rows by means of vertical select bars such as .Y' -in the same manner. as for the outlet contact fingers; As shown in Fig. 7, a codebar mechanism CB.

- i'sused to select a vertical bar such as V ;in accordance are selected individually by means of electro-magnets VM and VM As in Fig. 4, the actual displacement of the selected vertical bars is performed by means of the common bar H controlled by the servo-magnet VS. This common bar H need not necessarily control the displacement of the vertical bars V and V which can be displaced under the control of their individual magnet.

Also, although a code bar mechanism CB has been shown for controlling the selection of the vertical bars V V V,, it is evident that this could be replaced by individual electro-magnets for each vertical bar as in the case of the vertical bars V and V in which case the common bar H and the associated servomagnet VS can also be omitted. The selecting and operating mechanism for the horizontal bars will not be further described since it is identical to that already described in conjunction with Fig. 4.

The advantage of the type of construction disclosed in Figs. 6 and 7 resides in the fact that in this manner the number of vertical bars can be appreciably reduced as compared to the known arrangement shown in Figs. 3 and 4. Assuming that the multi-switch has a capacity of 100 outlets, and that the horizontal bars are movable in two opposite senses, the necessary number of vertical bars will be equal (in the known arrangement) to On the other hand, if intermediate conductors are used, e. g. between contact 1,, and contact 11-2, the number of vertical bars will only be i. e. V V V plus the two vertical bars V and V making a total of 27 vertical bars as compared to the original 100 and showing therefore a reduction of nearly 50%. This has also the advantage of reducing the largest dimension of the switch which is generally determined by the length of the common bar H and accordingly by the number of vertical bars in a row.

The actual size of the switch will not, however, be diminished since from that point of view the arrangement of Fig. 4 is the optimum one and since with the arrangements of Figs. 6 and 7 the reduction in length of the switch will be offset by the increase in depth, i. e. due to the fact that the fingers such as F will have to drive twice as many contacts, i. e. contacts 11-2 and contacts 13-4 instead of contacts 11-2 (Fig. 3).

However, the increase in size will be determined by the ratio between the number of intermediate contact fingers and the number of outlet contact fingers which, in the example considered, is equal to producing a percentage increase of 8% with respect to the switch of optimum size shown in Fig. 4. Since this is very small it can obviously be disregarded as compared with the advantage of using a substantially reduced number of vertical bars and accordingly a substantially reduced number of contact fingers.

A constructional embodiment of the switch schematically represented in Figs. 6 and 7 will now be described.

, This embodiment is shown in Figs. 8, 9 and 10 which should be assembled as indicated in Fig. 11 and which show a perspective view of a rnulti-switch. In its basic constructional aspect, the multi-switch is similar to that disclosed in the Belgian Patent Number 488,634 (I. Kruithof 40), in which to each inlet corresponds as indivilual switch, all the various individual switches being piled up on top of one another. Referring to Fig. 6, an individual switch such as that giving access from inlet No. 1, will therefore comprise the contacts 1a, 1b, 112, 13-4, 156, 17-8, etc. together with the necessary means for operating these contacts, it being understood that the total number of these contacts should, in fact, be multiplied by p, i.: e. the number of conductors necessary for each connection between an inlet and an outlet.

To fix ideas, it will be assumed by way of example, that for the multi-switch shown in Figs. 8, 9 and 10, the numher or inlets and corespondingly the number of individual switches is equal to 24, while the number of outlets is equal to 100, and the number of conductors for each connection is equal to 5. Referring more particularly to Figs. 8 and 9, which show the four corners of an individual switch, the latter will be assumed to correspond to inlet No. 8 to permit a systematic numbering of contacts in accordance with the scheme shown in Fig. 6.

The individual switch, e. g. that corresponding to inlet No. 8, is mounted on an insulated plate 1006 and essentially comprises a series of ten metal strips 81a, 82a, 83a, 84a, 85a and 81b, 82b, 83b, 84b, 25b, strips 85a, 81b and 82b only being shown. Each of these metal strips, e. g. 85a is provided with a number of oblique contact extensions which are designed to be driven into contact with vertical conductors such as 975 (the 5th conductor of outlet No. 97) or 985 (the 5th conductor of outlet No. 98) (Fig. 9). By referring to Fig. 6, it will therefore be appreciated that the metal strips such as 85a correspond with the so-called intermediate conductors which are shown in the latter figure, e. g. the conductor between contact 1a and any of the contacts such as 11-2, 156 etc. for inlet No. 1.

The vertical conductors such as 975 and 985 correspond with the fixed outlet conductors which are shown in Fig. 6. All the oblique contact extensions carry contacting strips of precious metal such as 897-985 which, in accordance with the lettering scheme used, refers to the contact permitting the connection of inlet No. 8 to either the fifth conductor of outlet No. 97, or the fifth conductor of outlet No. 98. Furthermore, at the end of each horizontal metal strip, there is also an oblique contact extension which is similar in design to the other contact extensions but which has the special purpose of connecting the metal strip to the inlet. For example, the horizontal strip 85a terminates into the oblique contact extension which carries the contacts 8a5, which, when driven either in the direction of the arrow f or f' will establish contact between the horizontal strip 85a and the inlet terminal P which is connected to the fifth conductor of inlet No. 8. It will be readily seen that in Fig. 6, this corresponds (for the inlet) to contact 1a effecting contact with terminal P to which inlet No. 1 is connected, noting, of course, that the references such as In and P in Fig; 6 cover an arbitrary number of contacts or terminals, e. g. 5, in accordance with the number (p) of conductors necessary for such inlet-tooutlet connection.

Taking a particular example of the inlet-to-outlet connection, from inlet No. 8 to outlet No. 100, both the contact extensions carrying respectively, the contacts SM. and 8991001 should be displaced, the first either in the sense of the arrow f or in the sense of the arrow 7%, and the second in the sense of the arrow f so as to establish an electric connection between the vertical conductor 1001 and the inlet terminal P' via the horizontal metal strip 81b. This is, of course, the required operation for one conductor only, i. e. the first and it should also be done simultaneously for the remaining conductors (2nd, 3rd, 4th and 5th) of the inlet-to-outlet connection (not shown).

These contact operations will be performed by means of the contact fingers such as F P To establish contact between the horizontal metal strip 81:: and the vertical conductor 1001, the finger P897400 will have to be displaced in the direction of the arrow f whereby, by means of the slot 1007, in the vertical part 1008 of the finger, the oblique contact extension carrying contacts 899-1001 will be driven to establish contact with the fixed vertical conductor 1001. To effect contact between the horizontal metal strip 81b and the inlet terminal P the finger F which is similar in design to the finger such as F3g7 m0, will also have to be driven but the sense of the displacement, i. e. f or f' is immaterial since the short vertical conductors 1009 and 1010 are i a electrically connected together and to the terminal P Thisis, of course, not the case for the vertical conductors shown at the left-hand side of the switch (Fig. 9), which are the vertical multiple conductors, e. g. 991, ancl'1001' which extend through the whole height of the multi-switch through holes which have been made in the insulated plates such as 1006'. In this manner, in accordance with the principles disclosed in the Belgian'Patent Number 488,634 (I. Kruithof 40), all the conductors of each inlet can be connected to the vertical conductors corresponding to the various outlets.

' Referring now to the manner in which the contact fingers such as F (intermediate contact finger) and F897' 10Q (outlet contact finger) are driven by a common horizontal bar corresponding to a particular inlet, i; e. H, (Fig. 7), the latter has been partially represented in Figs. 8

and 9 and is essentially a profiled ba'r provided with slots such as 1011, each slot corresponding to a particular finger such as P The front end 1012 of this finger which is displaced in the direction of its length, i. e. arrows f or f' is also provided with a slot 1013 in which the end 1014 or a part integral with the fork-shaped memher 1015 is engaged, this fork-shaped member 1015 being mechanically coupled, in a horizontal plane only, with the lever 1016 which is allowed to pivot in a vertical plane and more particularly in the sense of the arrow f inside the forked end 1017 of the member 1015 under the control of a helicoidal spring 1018.

Accordingly, when the lever 1016 has been moved downwards by some operating means which will be de scribed later, it will be engaged in the slot 1011 whereby. upon the horizontal bar H being displaced either in the sense of the arrow f or in the sense of the arrow f the lever 1016 will be driven in that sense and will, therefore, drive the fork-shaped member 1015 which will pivot in a horizontal plane around the pivot 1010', which, incidentally, also carries the spring 1018. Due to this dis placement and assuming the horizontal bar H has been driven in the sense of the arrow f the part 1014 mechanically coupled with the member 1015 will drive the contact finger P897400 in the sense of the arrow f whereby contact will be established between the horizontal met- 21 strip 81a (intermediate conductor) and the vertical conductor 1001. Simultaneously, of course, contacts will be established between the horizontal metal'strips 82b to 85!), and the vertical conductors 1002 to 1005.

By referring to Fig. 8, it will be observed that the manner in which the intermediate fingers such as F are driven, is identical to the above described manner and accordingly, when the horizontal bar H is longitudinally displaced in the sense of the arrow f and provided the lever 1020 has been'previously displaced downwards in the sense of the arrow f ,'the finger F will be displaced in the sense of the arrow f whereby contacts willbe established between the horizontal metal strip 81]) and the inlet terminal P as well as between the horizontal metal strips 82b 85b and the inlet terminals P to P (not shown).

Referring now to the manner in which the levers 1016 and 1020 are displaced downwards, this is achieved by means of the vertical bars such as those schematically shown in Fig. 7, i. e. the intermediate vertical bars V V and the outlet vertical bars V V etc. Since all these vertical bars are identical in construction and since they all operate in the same manner, only. one vertical bar V has been represented in Figs. 8 and 10. Each vertical bar V consists of a U-shaped profiled bar which is guided in a fixed plate 1021 (Fig. 10) at its bottom and also through an aperture such as 1022 (for bar V which is not shown) in the fixed part 1023 at its upper end, the top end of the bar VA having, of course, a cross section compatible with the shape of the aperture 1021. a

Parts ofthe middle side of the U-shaped profiled bar V have been cutaway so as to leave bridge-shaped parts such as 1024-around which resilient strips such as 1025" are fixed, secure fixing'being obtained by the projection 1026, these resilient parts being used to pushthe levers such as 1016 in a downward direction to place them under the control oftheir corresponding horizontal bar. It will be observed that the resilient part 1025 is T-shaped so that the top part of the T, 1027, is used to prevent undue upward displacement of the lever during the displacement of the hor'izontal bar.

It should be understood, that the necessary downward displacement of the vertical bar such as V is obtained under the control of an electro-magnet, i. e. VM (Fig. 7) which can be mechanically or otherwise associatedwith the vertical bar V After the horizontal bar H has driven the levers, e. g. 1016 and 1020, the corresponding vertical bar V (not shown) can now be restored to its original position, the association between the horizontal bar H and the levers 1016, 1020 being maintained under The re-' frictional pressure as will be explained later. storing of the vertical bar to'its original position will be carried out by means of the spring 1028.

Also by referring to Figs. 8 and 9, it will be observed that a centering mechanism has been provided for all the fingers such as P397400 (Fig. 9), this mechanism mainly comprising a spring 1020 which is respectively anchored around the small levers 1030 and 1031. These levers are respectively pivoted at one of their ends in apertures 1031 and 1033 respectively provided in a fixed part 1034. The other ends of these levers, i. e; 1035 and 1036 are therefore normally abutting against the vertical sides of the fixed part 1034 but project sufiiciently beyond the vertical part 1008 of the finger P897400 so that when the latter is displaced either in the sense of the arrow I or in the sense of the arrow f the displacement of the finger will be sufficient to either displace the end 1036' of the small lever 1031 or the end 1035 of the small lever 1030, whereby energy will be stored in-the spring-.1029 which will be used to restore the finger to a well defined rest position, the slot 1037 being provided to allow the displacement of the finger in the sense of the arrow f without causing the latter to be blocked against the small lever 1030.

It remains now to explain how the vertical bars, i. e. V and V were displaced downwards so as'to permit a connection between e. g. inlet No. 8 and e. g. outlet No. 100. This will be done with reference to vertical bar V2144 shown in Fig. 10, which is the sixth bar of a series of twenty-five outlet vertical bars. The bottom end of the vertical bar V2144 has an associated lever mechanism 1038 which can pivot with respect to the vertical bar at 1039. The horizontal part 1040 of the lever 1038 normally abuts against an extension 1041 which is provided on the common horizontal bar H (Fig. 7). The remaining part 1042 of the arm 1040 is located above a set of code bars CB CB CB CB; and CB These code bars are the essential part of the code bar mechanism CB schematically represented in Fig. 7 and are each provided with slots in such a manner that when a particular combination of code bars is displaced in the direction of the arrow f slots will be aligned at one particular position along the length of said code bars whereby a lever arm such as 1042 will be able to drop in these slots. For the particular vertical bar considered, i. e. V when the code bars CB and CB are displaced in the direction of the arrow f while the remaining code bars CB CB, and CB remain in their rest position (as shown),'the'lever arm 1042 will be free to drop in the slots 1043, 104d, 1045, 1046 and 1047 assuming, of course, that the downward movement of the lever arm 104-2 is no longer prevented by the extension 1041. The means for displacing the code bars have not been shown since any suitable rneans can be used, so that eachcode bar is operated by its respective code bar magnet,

.e. g. CM; (Fig. 7) for code bar CB .(Fig. 10)...

Accordingly, once the vertical bar V2144 has been selected by the energization of the code bar magnets CM, and CM the slots 1043, 1044, 1045, 1046 and 1047 will be aligned, and by displacing the common horizontal bar H in the sense of the arrow f the lever arrangement 1038 will pivot in an anti-clockwise direction, the lever arm 1042 falling inside the various slots while at the same time, the other arm 1048, which is provided with a hook 1049, will also pivot in an anti-clockwise direction so that the part 1050 of the common bar H will cooperate with the hook 1049, whereby, during the further downward displacement of the common bar H, the hook 1049 will be driven downwards and accordingly will drive the vertical bar V2144 in the direction of the arrow f For the connection which has been considered above as an example, it is, of course, the vertical bar V which will have to be displaced downwards and this may occur by the displacement of the code bars CB CB; and C13,. The code bar guide rods 1051 and 1052 which have been shown in Fig. 10, are provided with spacers such as 1053 to maintain the proper spacing between the various code bars.

It has been mentioned above that any operated finger is maintained in its actuated position by frictional pressure between e. g. the horizontal bar H and the lever 1016. This frictional pressure is quite sufiicient to ensure a safe operation, since pressure is exerted not only by the centering spring 1029 but also by the back pressure on all the ten contact extensions such as 899-1001.

Referring to Fig. 6, and more particularly to the connection between terminals P and P; shown in dotted lines, it will be readily appreciated that if this connection is omitted, the multi-switch can now provide ten conductors for each inlet-to-outlet connection instead of five with, of course, a corresponding diminution in the number of outlets, which becomes fifty instead of one hundred. Of course, if the multi-switch is to be used with ten conductors for each connection, the two intermediate contact fingers should always be in an actuated position, or else, their corresponding contacts should be by-passed to the inlet conductors.

It should be noted that although the embodiment of the multi-switch shown in Figs. 8 to 10 shows a code bar mechanism for selecting a particular vertical bar, this is by no means essential and individual electro-magnets could also be used to control each vertical bar. Also, the use of servo-mechanisms such as the horizontal bar H and the vertical bars VL and VR (Fig. 7), are not essential and may be omitted.

Further, the invention is neither restricted to a switch of any particular capacity nor to a switch in which only two intermediate vertical bars are used. For example, considering a multi-switch with 100 outlets, four intermediate vertical bars could be used whereby the number of ordinary bars would be reduced to thirteen (producing in fact a switch having a capacity of 13 4 2=104 outlets), whereby the total number of vertical bars would be reduced to 13 +4=17, which is still less than the 27 vertical bars needed for the embodiment shown in Figs. 9-10. However, with such an arrangement, each finger now controls 4x5 contacts, i. e. 20 contacts instead of 10, and this may become a limiting factor. The real disadvantage, however, will be the increase in the size of the switch as compared to the optimum size and therefore the use of more than two intermediate vertical bars is probably only of advantage (for economic reasons) when the multi-switch has a larger number of outlets.

For example, in a multi-switch having 500 outlets, 4 intermediate vertical bars can be used whereby the number of outlet vertical bars is only 63, bringing the total number of vertical bars to 63 +4=67 instead of 250, which would be the required number if intermediate vertical bars are not used, and if each connection is established over a single contact only. In this case, the reduction in the number of vertical bars is striking and on the other hand, the inbringing the total number of vertical bars down to 50+5=55 and with an increase of size, as compared with the optimum, of only 10%.

While the principles of the invention have been described above in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of the invention.

We claim:

1. A clutch operating mechanism for an electric multiswitch comprising a plurality of spaced clutch members extending in a first plane, first actuating means for moving said members in a direction perpendicular to said first plane, a plurality of spaced actuating elements extending in a second plane perpendicular to said first plane for moving said clutch members into clutching relation with said first actuating means, second actuating means for moving said elements, a plurality of parallel movable code bars extending in a direction having a third plane, said third plane perpendicular to both said first and said second planes, a plurality of separate latch means, each pivotally connected to a different one of said elements, said latch means having a first portion and a second portion, said first portion extending transversely across said code bars and adapted to engage said bars under control of said second actuating means, said second portion adapted to be engaged by said second actuating means upon movement of said code bars to a predetermined position said first portion adapted to be pivoted against said code bars under control of said actuating means, and means connected with said second actuating means for restoring said latch means to disengage same both from said code bars and said second actuating means.

2. A clutch operating mechanism as claimed in claim 1 wherein each of said elements comprises a member having a plurality of spaced projecting strips extending perpendicularly therefrom, each strip associated with a different one of said clutch members and adapted to remain in movable engagement therewith.

3. A clutch operating mechanism as claimed in claim 2, wherein said strips have a T-shaped portion adapted to remain in engagement with said clutch members when said members have been moved by said first actuating means.

4. A clutch operating mechanism as claimed in claim 1, wherein the first portion of said latch means comprises a sensing arm adapted to engage said code bars and said second portion comprises a latch piece extending perpendicularly to said sensing arm.

5. A clutch operating mechanism as claimed in claim 1, wherein said latch means further comprises a cam surface adapted to cooperate with said restoring means.

6. A clutch operating mechanism as claimed in claim 1, further comprising a pair of spaced, fixed guide plates, each having a plurality of spaced slots therein, the slots in each plate in register with the corresponding slots in the other, each actuating element adapted to move through a corresponding pair of said slots.

7. An electric cross-bar multi-switch for use in a telecommunications system comprising a first set of spaced parallel conductors (e. g. outlet conductors) arranged in rows in two directions at right angles, a second set of parallel conductors substantially perpendicular to those lit of said first set and interleaved therewith so as to form spaced crossing points,- said second set of conductorscomprising a first plurality of spaced movable" contacts, first means for moving said contacts in either one of two directions substantially perpendicular to said first set of conductors to make electrical contact with either one of two of said first set of conductors according to the direction in which they are moved, a third set'of conductors (e. g. inlet conductors), said second set of conductors comprising further movable contacts, additional means for moving said further contacts to make contact with either one of a pair of said third set of conductors, the conductors of each said third pair of conductors being electrically connected together and common actuating means for actuating both said first moving means and said additional moving means, whereby a circuit path from a given conductor of said third set to a given conductor of said first set, includes a given conductor of said second set via a first movable contact and a further movable contact associated therewith.

8. An electric switch as claimed in claim 7 wherein said first moving means comprises a plurality of parallel outlet contact fingers each adapted to move corresponding ones of said first movable contacts associated with conductors of said second set, said additional moving means comprising an intermediate contact finger mounted parallel to said plurality of outlet contact'fingers and adapted to move corresponding ones of said further movable contacts associated with conductors of said second set, said common actuating means comprising a drive-bar, separate clutch means intermediate each of said contact fingetsand said drive-bar, said drive -bar adapted to move in a selected one of said outlet contactfing'ers and said intermediate contact finger simultaneously in the desired 7 direction, whereby'ea'ch connection between an inlet and 1 an outlet is established through two electrical connections common means for operating said select bars, said operated select bars adapted to couple said clutch mechanisms to said-common drive-bar.

10. A- switch as claimed in claim 9 and wherein said means for selecting a select-bar extending'transverse of said outlet contact fingers comprises a code bar mechamsm.

' References Cited in the file of thispatent UNITED STATES PATENTS 1,339,001 Reynolds May 4, 1920 1,564,231 Goff Dec. 8, 1925 2,082,911- Schneckloth June 8, 1937 2,653,486 Bracke et al. Sept. 29, 1953 Montchausse c Dec. 29, 1953 

